The advent of the tapeless workflow for video images has simplified production and post-production, amounting to significant cost saving. For example, output from a digital camera can be directly converted to a digital intermediate format, without having to undergo the typically expensive process of digitizing (or scanning) film. In addition, post-production such as editing and color correction can be done on relatively inexpensive desktop systems.
In a tapeless workflow as is used in television or movie production, it may be required that the images be acquired and outputted with as minimal in-camera processing as possible. This requirement allows for more latitude in altering the footage for post-production, such as changing the exposure and color. As such, this requirement typically translates to outputting raw sensor data.
One trend in video capture is high definition capture. In this regard, the acquisition format is not necessarily the same as the delivery format. For an example in acquisition format, movie cameras can often support 4K capture or higher, where 4K describes the horizontal pixel dimension. However, if the delivery format is HDTV, then the resolution is typically 1920×1080, which is smaller. A common approach is to capture as high a resolution as possible, and to downsample in post-production.
Another trend for video capture is high frame rate. Similar to resolution, the acquisition frame rate may not be the same as the delivery frame rate. For example, one reason for the acquisition frame rate to be higher than the delivery frame rate is to achieve a slow motion effect, which can be best for fast action sequences such as explosions. In addition, as high end display/TV systems tend to support high refresh rates, there is a tendency for newer broadcasting or video standards to allow higher frame rates.
As such, there are trends to support high resolution and high frame rate for video capture. By using raw sensor data output, however, data transfer rate and storage capacity of recording mediums can be limiting factors. Accordingly, there is a desire to output raw sensor data with reduced data transfer rate.